Apparatus for die casting



S. C. HOEY APPARATUS FOR DIE CASTING Filed 'July 13, 1923 INVENTORSamue/ C. Hoe v,

WITNESSES:

Patented Dec. 1, 1925.

UNITED srrss PATENT OFFICE.

SAMUEL C. HOEY, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSEELECTRIC & MANUFACTURING- COMPANY, A CORPORATION OF PENNSYLVANIA.

APPARATUS FOR DIE CASTING.

Ap'plicationfiled July 13, 1923. Serial uo.'e51,'221.

To all 107mm it may concern:

Be it known that I, SAMUEL C. Hour, a citizen of the United States, anda resident of Wilkinsburg, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement in Apparatusfor DieCasting, of which the following is a specification.

My invention relates to pressure casting devices, more especially to adevice for casting rotors for dynamo electric machines.

It is among the objects of my invention to provide a device which shallbe of simple, compact and inexpensive construction which shall beadapted to the casting of metal bodies of uniform quality and inproduction quantities.

In the process of die casting, which is a method of casting molten metalunder pressure in a die or mold of the shape and contour of the body tobe formed, the metal is usually contained in a reservoir associated withthe die or mold with communicating openings or ports provided to permitthe flow of the metal into the die. The ports may consist of one or moreconstricted openings depending upon the structure to be cast and theopenings are ordinarily straight passages to offer the least resistanceto the flow of the molten metal.

I have found that in casting bodies of irregular cross-section. such assquirrel cage rotors for dynamo-electric machines, the shape of theports governs the quality of the casting in that the shape of theopenings regulates the disposition of the molten metal as it is forcedinto the die or mold.

In squirrel cage rotors which consist of slotted laminations havingconductor bars extending through the slots and united by end rings, theforming of the conductor bars by pressure casting prevents perfectformation of the end ring farther from the ports or openings due to theair and gases which are trapped in the mold by the incoming metal.

My present invention is directed to a device having specially shapedports which retard the velocity of the fluid metal to effect a uniformrising thereof that forces the gases and air out through the vents atthe top of the mold and permits of forming a full. end ring with aminimum amount of blow-holes or other irregularities in the casting.

In the accompanying drawing constituting a part hereof and in which likereference characters designate like parts, I

Fig. 1 is a vertical cross-sectional view of a pressure casting deviceembodying the principles of my invention,

Fig. 2 is a cross-sectional view of a base plate utilized in the die ormold of the deviceshown in Fig. 1, and

Fig. 3 is a bottom plan view of the base plate.

Referring'toFig. 1, the pressure casting device therein illustratedcomprises a mold or die consisting of a matrix 1 of ring shape that ismounted upon a base. 2 comprising a reservoir or chamber 3 having apiston member 4c disposed therein. A baffle wall 5, provided with acentral opening 6, is located 'intermediate the mold 1 and reservoir 3.A base plate-7 having a plurality of spiral ports 8 and a centralrecessed portion 9 is disposed in the mold 1 on top of the wall member Iin central alinement with the opening 6. A clamping plate 10 is securedto the matrix 1 by a plurality of bolts 11. The base portion 2 isprovided with openings 12 by which it may be clamped to a bed or worktable as desired.

The operation of this device is briefly as follows: A rotor 13comprising a plurality of superposed sheet iron laminations is assembledand secured in the matrix 1 between the base plate 7 and the clampingplate 10 in the manner shown in Fig. 1. The reservoir 3 is filled withmolten metal, such as copper, aluminum, an aluminum alloy or the likeand the piston 4 is actuated to cause the metal to advance against thebaflie plate 5, forcing the metal through the central opening 6 into therecess 9 of the pressure plate 7 and through the spiral ports 8 into thematrix 1. The metal then slowly and uniformly rises filling up the space15, the slots 16 and the space 17 forcing out any gases or trapped airthrough the vent holes 18 provided in the clamping plate 10. The spiralopenings 8 function to effect a uniform rising of the metal in thematrix which prevents the trapping of air or gases in the body, thusproducing a casting having a homogeneous structure throughout. Thespaces 15 and 17 receive metal to constitute the end rings and the slots16 receive metal for the conductor bars of the cast body, whichconstitutes a rotor of integral structure.

If vertical ports in alinement with the portions to be cast, as isordinarily used in pressure devices, were used. the metal would fill thespaces in an irregular manner so as to produce trapped air pockets andother irregularities in the casting. It is evident from the foregoingdescription of my invention that a pressure casting device such as isdescribed herein may. be utilized in casting bodies of special shapes inan eflicient and expedient manner and that such a device is especiallyadapted to cast the end rings and conductor body portions of squirrelcage rotors of dynamo-electric machines.

Although I have described a specific embodiment of my invention, it willbe obvious to those skilled in the art that the general design andproportions of the device illus trated herein may be varied and thenumber and shape of the ports may be changed without departing from thespirit of my invention.

1 claim as my invention 1. A pressure casting device comprising a mold,a reservoir associated therewith, a bafiie Wall intermediate said moldand reservoir having radial communicating ports and means for emptyingthe contents of the reservoir through said ports.

A pressure casting device comprising a mold, a reservoir associatedtherewith, a baffle wall intermediate said mold and reservoir, said wallhaving a central opening and a plurality of spiral ports communicatingtherewith.

3. A pressure casting device comprising a mold, a reservoir associatedtherewith, a battle wall intermediate said mold and reservoir having acentral opening therein, and a base plate in said mold disposed abovethe opening of said wall having a plurality of spiral portsconnnunicating with the said opening.

4-. A pressure casting device comprising a mold that is adapted toreceive a body in or about which a casting is to be formed, a base platefor said mold having a plurality of spiral ports formed therein andmeans for filling the mold through said ports.

5. A pressure casting device comprising a mold and a reservoirassociated therewith and means for discharging a liquid from saidreservoir into said mold at a constant velocity, said means comprising aplurality of spiral ports and a pressure actuated piston.

In testimony whereof, I have hereunto subscribed my name this 2nd day ofJuly, 1923.

SAMUEL C. HOEY;

